Astronomy Ch 3

Front 1

What is science?

Back 1

a way to learn about nature through constant trial and error experiments.

Front 2

Practical benifits of astronomy in antiquity

Back 2

time keeping, keeping track of seasons and navigation

Front 3

What could ancient central african's do with astronomy that was so impressive?

Back 3

they could predict rainfall patterns by making careful observations of the moon. In tropical regins where there are distinct rainy and dry seasons the orientation of the cresent moon can be used to predict how much rainfall should be expected over coming days and weeks

Front 4

How does astronomy affect the measurement of time?

Back 4

day length is the time it takes the sun to make one full circuit of the sky.

The length of the month comes from the moons cycle of phases.

the length of the year is based on the cycle of the seasons.

seven days of the week were named after seven planets of ancient times.

Front 5

what were the seven days of the week named after?

Back 5

seven ancient planets. sun,moon, mercury, venus, mars, jupitur, saturn.

Front 6

What were some ways in which people used astronomy to determine the time of day?

Back 6

many cultures probably used sticks and shadows they cast as simple sundials.

Egyptians made huge obelisks, often decorated in homage to the sun.

at night people could estimate time from the position and phase of the moon or by observing the constellations visable at a particular time.

Front 7

How did Egyptians create the first clock? how does this clock reflect modern timekeeping?

Back 7

cataloged where particular stars appeared in sky at various times of night throught the year. the catalog could use star clock to estimate the time of night.

Egyptians divided day and night into twelve equal parts each. anti meridiam, post meridiam.

Front 8

1500 egypt

Back 8

egyptians abandon star clocks and use clocks that measure time by the flow of water through an opening like an hourglass. ADVantage is they worked even when it was cloudy.

Front 9

Templo Mayor

Back 9

twin temples on a falt topped pyramid. sun rises through notch between the temples on teh equinoces.

Front 10

Why do many cultures align their building sand streets with the directions? n,e,s,w

Back 10

made it easier to keep track of the changing rise and set positions of the sun over the course of a year.

Front 11

What is the sun dagger?

Back 11

made by pueblo people in chaco canyon, new mexico.

three large slabs of rock lie in front of a carved spiral in such a way that they produced special patterns of light and shadow at different times of year.

Front 12

what is a solar calender

Back 12

a calendar that is sychronized with the seasons so that seasonal events such as the solstices and equonoxes occur on approximately the same dates each year.

currently used

Front 13

ehat is the lunar calander?

Back 13

calenders whos aim is to say syncronized with the mon and it's 29 1/2 day cycl of phases. this is so the moon phase is always the same on the first day of each month.

The lunar calander has approximately 11 days fewer than a calender based on the sun.

still in use in the muslim religion.

Front 14

metonic cycle

Back 14

19 year son a solar calander is almost precisely 235 months on a lunar calender. as a result, the lunar phases repeat on the same date every 19 years.

Front 15

archaeoastronomy

Back 15

peicing together astrnomical achievements by studying the physical evidence they left behind.

Front 16

nazca ines

Back 16

point to places where the sun or bright stars rise at particular times of year. Speculation. some people think they may be constellations recognized by the people who lived in the region.

Front 17

What are the three major greek innovations that helped pave the way for modern science?

Back 17

tradition of trying to understand nature without relying on supernationral explaniations and of working communally to debate and challenge eachothers ideas.

second the greeks used mathematics to give precision to their ideas.

greeks also saw the power of reasoning from observations. they understood that an explanation could not be right if it disagreed with observed facts.

Front 18

Models of nature

Back 18

a conceptual representation created to explain and predict observed phenomena

Front 19

Alexander the great

Back 19

conquest spread creek knowledge in 356-323 bc.

library of alexandria in egypt. may have held as many as a half million books handwritten on papyrus scrolls.

Front 20

Where was scientific progress occurring durring the dark ages?

Back 20

islamic scholars sought knowlege in hopes to better understand the wisdom of allah.

Front 21

house of wisdom

Back 21

employed jews, christians and muslims to work togehter in scholarly pursuits using the translated gree scientific manuscripts as building blocks. Most official names of constellations and stars come from arabic becous of eht ework of the scholars at baghdad.

were in touch with scholars in baghdad and china, india.

Front 22

how did the knowlege of the dark ages learned in the islamic world travel to europe?

Back 22

when the byzantine capital of constantinople fell to the turks in 1453 many eastern scholars headed west to europe carrying with them the knowlege that helped ignite the european renaissance.

Front 23

Greek Geocentric model of the cosmos

Back 23

a spherical earth at the center of the universe.

Front 24

Thales

Back 24

first to scientifically try to explain what hte universe is made of. philosophized that it was a flat disk, floating in a sea of infinite ocean.

Front 25

anaximander

Back 25

thorized that earth floated in empty space surrounded by a sphere of stars and two separate rings along which teh sun and moon travel.

first to imagine earth to be cilinder- deducted this due to changes in teh constellations with latitude.

Front 26

Pythagoras

Back 26

c. 560-480 bc. greek. taught that earht was round. envisiond earth as a sphere floating in teh center of teh celestial sphere. philisophical motivations. Considered spheres to be gemetrically perfect.

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plato

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theororized all heavenly objects move in perfect circles at constant speeds and therefore must reside on huge spheres encircling earth. belief in perfection influenced astronomical models for the next 2000 years.

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Exodus

Back 28

created a mode in which teh sun, the moon, and the planets each ahd their own spheres nested within several otehr spheres. individually teh nested spheres turned in perfect circles.

exodus was able to make them work together in a way that reproduced many of the observed motions of the sun, moon and planets.

Front 29

Aristotle. 384-322 bc.

Back 29

his model of the universe envisioned all spheres responsible for celestial motion were transparent and interconnected like the gears of a giant machine. earths position was explained as a consequence as gravety. argued gravity pulled heavier things towards the center of the universe.

Front 30

Ptolemy's syntesis

Back 30

claudius ptolemy placed earth at the center of the universe. to explain retrograde motion ptolemy suggested each planet moved around earth on a small circle that turned upon a larger circle.

adapted and syntesized earlier ideas into a single system that agreed quite well with the astronomical observations available at the time. produced a model that could correctly forecast future planetary positions to within a few degrees of arc.

in arrabic they gave his book teh title almagest.

Front 31

deferent and epicycle

Back 31

deferent is the larger circle in which the smaller circle, the epicycle, turns on.

Front 32

hipparchus

Back 32

developed the circle upon circle idea into a model that could predict pletary positions.

Front 33

Copernicus

Back 33

born 1473. tried aristachus's sun-centered idea. developed simple geometric relationships that allowed him to calculate each planet's orbital period aroudn the sun and its relative distance from the sun in terms of eart-sun distance.

published concerning the revolutions of the heavenly spheres on the day he died in 1543.
held too steadfast to the idea that heavenly motion must occur in perfect circles.

Front 34

Tycho

Back 34

1546-1601

observed a new star in 1572, nova, by masuring its parallax and comparing it to the parallax of the moon. concluded it was much further away than the moon. [it was actually a supernova]

King Freddrick allowed him to build an unparreled observatory.
after freddricks death german emperor rudolf supported him.

Developed a naked eye observations of the galaxy accurrate to within the thickness of a fingernail archminute. Best set of naked eye observations.

advocated a model where the sun orbits earth and all otehr planets orbit the sun.

Front 35

Kepler

Back 35

Employee of Tycho. Small descrepencies between his observations and tychos led him to abandon the idea of circlular orbits.

suggested that planetary motion might be the result of a force from the sun.

Front 36

ellipse

Back 36

An ellipse is (sort of) an oval shape, with two interior points called foci (singular: focus), a long axis (the major axis), a short axis (the minor axis), and a center (which should under no circumstances be confused with a focus).

Front 37

semi-major axis

Back 37

Half of the major axis, also the average sun-planet distance.

Front 38

eccentricity

Back 38

he number that characterizes how flat the ellipse looks compared to a perfect circle.
The eccentricity e can be calculated by taking the center-to-focus distance and dividing it by the semi-major axis distance.

Front 39

What are keplers three lawas of planetary motion

Back 39

the orbit of each planet around the sun is an ellipse with the sun at one focus. Planets distance fromt eh sun varies during its orbit.

as a planet moves around its orbit it sweeks out equal areas in equal times. planet moves a greater distance when it is near the closest point to the sun and does the same when near the furthest.

more distante planets orbit the sun at slower average speeds, obeying a precise mathematical relationship

Front 40

Perihelium vrs aphelion

Back 40

closest point of orbit to the sun

furthest point of orbit from the sun. The semimajor axis is the average distance from the sun. the planet moves faster when it is closer to the sun, slower when it is further.

Front 41

How did Galileo solidify the copernican revolution?

Back 41

1564-1642. a moving ball remains in motion unless a force stops it.
Built telescope in 1609. Shattered idea of perfection by noticing sun spots and mountains on moon (shadows).
Observation of the absense of observable stellar parallax. observed the stars were far more numerous and more distant than tycho had believed.

Front 42

Stellar Parallax

Back 42

theory by Tycho. Stellar parallax is so small (as to be unobservable until the 19th century) that it was used as a scientific argument against heliocentrism during the early modern age. the effect would be undetectable if the stars were far enough away, but for various reasons such gigantic distances involved seemed entirely implausible: it was one of Tycho Brahe's principal objections to Copernican heliocentrism that in order for it to be compatible with the lack of observable stellar parallax, there would have to be an enormous and unlikely void between the orbit of Saturn and the eighth sphere (the fixed stars).[4]

Front 43

What were galileo's earliest discoveries through the telescope?

Back 43

he observed four moons clearly orbiting jupitor, not earth.

observed venus goes through phases in a way that makes sense only if it orbits the sun and not earth

Front 44

What is Galileo's history with the church?

Back 44

ordered to recant his claim that earth orbits the sun. at nearly 70, and afraid he did as told.

was formally vindicated in 1992.
in 1757 all works backing the idea of a sun-centered solar system were removed from the index of banned books.

Front 45

What are the three hallmarks of science?

Back 45

modern science seeks explanations for observed phenomena that rely solely on natural causes.

science progresses through the creation and testing of models of nature that explain the observations as simply as possible

a scientific model must make testable predictions about natural phenomena that will force us to revise or abandon the model if the predictions do not agree with observations.

Front 46

Occam's Razor

Back 46

The idea that scienctists should prefer the simpler of two models that agree equally well with obasrevations

Front 47

Verifiable observations

Back 47

having the option to varify scientific testimonies yourself using verifiable evidence.

Front 48

Psudoscience

Back 48

false science-claims about the natural world that seem to be based on observational evidence but do not treat evidence in a truely scientific way.

Front 49

Objectivity in science

Back 49

all people shoudl be able to find teh same results.

Front 50

Scientific theory

Back 50

a model makes predictions that survive repeated and varied testing. must be supported by a large, compelling body of evidence.

Front 51

How is astrology different than astronomy?

Back 51

astrology believes that various positions of the sun, moon, planets, stars, ect influence human events.

many astronomers continued to practice astrology. kelpler cast numerous horoscopes.

Front 52

In what ways do all humans use scientific thinking?

Back 52

scientific thinking relies on teh same type of trial and error thinking that we use in our every day lives but in a carefully organized way.

Front 53

how is modern science rooted in anchient astronomy?

Back 53

ancient astronomers were accomplished observers who learned to tell the time of day and time of year to track the cycles of the moon and to observe planets and stars.

Front 54

Why does modern science trace its roots to teh greeks?

Back 54

the greeks developed models of nature and emphasized the importance of agreement between the predictions of those mondel snad observations in nature

Front 55

how did the greeks explain planetary motion

Back 55

the greek geocentric model reached its culination with the ptolemaic model which explained apparent retrograde motion by having each planet move on a small circle whose center moves around earth on a larger circle

Front 56

how did compernicus, tycho, and kepler challenge the earth centered model?

Back 56

copernicus created teh sun centered model to replaace the ptolemaic model but still used perfect circles

tychos acurate naked eye observations provided the data needed to improve on compernicus' model

kepler developed a model of planetary motion that fit tychos data.

Front 57

what are keplers three laws of planetary motion

Back 57

the orbit of each planet is an ellipse with the sun at one focus

as a planet moves around its orbit it sweeps out equal areas in equal times

more distant planets orbit the sun at slower aver speeds obeying the mathematical relationship p2=a2

Front 58

how did galileo solidify the copernican revolution

Back 58

overcame remaining objections to teh copernican idea of earth as a plent orbiting the sun.

Front 59

how can we distinguish science from nonscience?

Back 59

science generally exhibits three halmarks a) explanations for observed phenom that rely solely on natural causes b) science progresses through the creation and testing of models of nature that expain the observations as simply as possible c) a scientific model must make testable predictions about natural phenomena that owuld forse us to revise or abandon the mode if the prediction did not agree with the observations

Front 60

what is a scientific theory?

Back 60

a simple and powerful model that explains a variety of observations using just a few general principals and has been verified by repeated and varied testing

Front 61

how is astrology different froma stronomy?

Back 61

astronomy is a modern science that has taught us about the universe. astrology is a serch for hidden influences on human lives based on teh apparent position sof planets and stars in the sky and does not follow the tenets of science

Front 62

does astrology have scientific validity?

Back 62

have shown astrology predictions do not prove to be accurate more than we can expect by chance. so, no.

Front 63

1) How did an ancient Egyptian “hour” compare to the one we use today?
a) It was shorter (about 45 minutes long).
b) It varied in length depending on the seasons.
c) It was defined by whoever was Pharaoh at the time.
d) It divided the day into 24 equal parts

Back 63

b) It varied in length depending on the seasons
They broke up their days and nights into 12 sections, and since the amount of daylight
changes with the seasons, so too did the length of the hour.

Front 64

2) How did Eratosthenes determine the size of the Earth?
a) Measuring the distance between two cities and considering the position of the
sun at noon on the summer solstice in both places.
b) Careful observation of the stars and planets, and how their positions change
throughout the seasons with respect to manmade structures.
c) Google.
d) Measuring the curvature of Earth’s shadow during lunar eclipses.

Back 64

a) Measuring the distance between two cities and considering the position of the
sun at noon on the summer solstice in both places

None of the other methods would have worked: the positions of the stars and planets
don’t depend on the size of the Earth in a way that was measurable at the time, Google
hadn’t been invented yet and the eclipse method would require one to know the
distance from the Earth to the Moon.

Front 65

3) Ptolemy created an astronomical model that allowed for very accurate
predictions of the positions of the stars and planets. Why is his model no longer
favoured today?
a) It was not able to account for retrograde motion of the planets .
b) It relied heavily on supernatural explanations for the motions of the planets.
c) He assumed that all planets would follow elliptical orbits.
d) His model had the Earth as the center of the solar system.

Back 65

d) His model had the Earth as the center of the solar system.
After adding epicycles to the model, the retrograde motion was (somewhat) explained.
However, his model fell out of favor when Copernicus, Brahe and Kepler came up with
a better Heliocentric (sun centered) model for the solar system.

Front 66

4) During the Dark Ages, a time when scientific thinking was rapidly regressing in
Europe, where did the majority of scientific advancement take place?a) The Americas.
b) Australia.
c) The Middle East.
d) Middle Earth.

Back 66

c) The Middle East

E.g. Baghdad, in what is now Iraq, became a centre of scientific achievement. They
worked on developing the theories of the Greeks, and translating and preserving their
texts.

Front 67

5) What was Nicholas Copernicus’ most notable contribution to modern day
Astronomy?
a) He was able to improve on Ptolemy’s model by adding extra epicycles to
planetary motion while keeping the Earth at the centre.
b) He proposed a simplified Heliocentric model of the solar system.
c) He drastically improved upon the telescope and was the first to observe Jupiter’s
moons.
d) He proposed Copernicus’ Three Laws of Planetary Motion.

Back 67

b) He proposed a simplified Heliocentric model of the solar system

Copernicus realized that some of the complex problems in the Geocentric (Earth
centered) model would not occur in a sun-centered model. He still used circular orbits
to describe the motions of the planets around the Sun, which caused his predictions to
be inaccurate.

Front 68

6) How did Tycho Brahe contribute to the field of Astronomy?
a) He recruited Kepler as his assistant for analyzing his observational data.
b) He determined that comets and novae occur much further away than the moon.
c) He took extremely detailed and accurate measurements of the positions of
heavenly bodies.
d) all of the above.

Back 68

Brahe observed distant objects and used the method of parallax to compare their
distance to that of the Moon. He also created a large collection of measurements that
Kepler would later use to formulate his laws of motion. And he recruited Kepler.

Front 69

7) How did Johannes Kepler contribute to Astronomy?
a) He proved that Brahe’s measurements of the heavenly bodies were wrong.
b) He showed that comets also move in perfect circles around the Sun.
c) He determined that planets move in ellipses, and proposed Kepler’s Laws of
Planetary Motion.
d) He discovered the first 4 moons around Jupiter.

Back 69

c) He determined that planets move in ellipses, and proposed Kepler’s Laws of
Planetary Motion

c) He determined that planets move in ellipses, and proposed Kepler’s Laws of
Planetary Motion

Front 70

8) Which of the following is not a possible orbit in the context of Kepler’s First Law?
a) A planet moves in an ellipse with the Sun at one focus.
b) A planet moves in a circle with the Sun at the centre.
c) A planet moves in an ellipse with the Sun at the centre.
d) All are possible

Back 70

A planet moving in an ellipse would have the Sun at one focus of the ellipse. A circle is
like an ellipse with both foci at the centre.

Front 71

9) Kepler’s Second Law tells us that a planet with an elliptical orbit will:
a) move more slowly when it is further from the Sun.
b) move faster when it is further from the Sun.
c) move at a constant speed around the Sun, regardless of its orbit.
d) slowly spiral into the sun.

Back 71

Kepler’s Second Law formally states that a planet will sweep out equal areas in equal
times as it passes around the Sun (i.e. its “areal velocity” is constant). In order for it to
do this, it needs to travel at a faster rate when its distance from the Sun is smaller.

Front 72

10) Kepler’s Third Law relates the following characteristics of a planet:
a) period and rotational speed.
b) average distance and size.
c) average distance and period.
d) rotational speed and size

Back 72

c.
Kepler’s Third Law states that the cube of the average distance of a planet is related to
the square of its orbital period. As an equation,
a3 = p2
where a is in Astronomical Units (the distance from the Sun to the Earth) and p is in
Earth years.

Front 73

11) How did Galileo contribute to modern Astronomy?
a) He refined the telescope for use as a scientific instrument.
b) He discovered the largest 4 moons around Jupiter.
c) He showed that Venus actually rotated around the Sun, not the Earth.
d) all of the above.

Back 73

Galileo greatly improved the power and precision of the telescope, allowing him to see
the four large moons of Jupiter (now known as the Galilean moons). This was a serious
blow to the idea that every celestial body rotated around the Earth. As well, he
observed phases of Venus, which only made sense if both were considered to be
rotating around the Sun.